Otto n



UNITED STATES PATENTjiOFFICE, f a

OTTON. wlrr, 0F WESTE-ND, NEAR BERLIN, Assicnon TO THE BADISCH'E I ANIL'IN AND SODA FABRIK,

PURPLE AZO DVYE-SVTUFF.

on MANNHEIM, GERMANY) 7 SPECIFICATION forming part of Letters Patent N5. 381,046, dated April 10. 1888.

Application filed January 28, 1888,

To aZZ whom it may concern: V Be it known that-.1, OTTO N. Wrrr, doctor of philosophy, a citizen of Switzerland, reside ing at Westend, near Berlin, in the Kingdom of Prussia and Empire of Germany, haveinvented new and useful Improvements in the Manufacture of a Purple Coloring-Matter or Dye-Stuff, of which the following is a specification.

This invention relates to the manufactureof a purple coloring-matter or dye-stud of the class commonly known as am dyestuffs.

To carry out my invention I proceed as follows: I take 18.5 parts, by weight, of binitroaniline of the modification known to chemists as the assymmetrical one, discovered by Gottlieb and me] ting at 180 centigrade. I then transform the said binitro-aniline into its diazo derivative by using any or eitherof the wellknown methods for the purpose. As an example, I describe the following method, without, however, limiting myself to its exclusive use: Iintroduce the before-named quantity of binitro aniline into one hundred parts, by

weight, of ordinary concentrated or rectified sulphuric acid, in, which'previously 6.9 parts, by weight, of sodic nitrite, or 3.8 parts, by weight, of nitrous anhydride have been dissolved. When all the binitro-aniline has been taken up and dissolved by the acid, Ipourthe solution thus obtained upon choppedice, and

in this manner I prepare ansaqueous solution "mon salt. I

-This new dyestuff dyes either Wool or silk. :cg;

aammonia under pressure,-together with one hundred and sixty-five parts, by weight, of o sodic acetate (taken as drylin aboutone thousand parts of water. Thissolution I mix in the cold,and under constant vigorous stirring, with the solution of binitro-diazo-benzine sulphate, v

1 45 The dye-stuff is formed at once, but remains obtained as above described.

in the solution, fromwhich it maybe separated by the addition of salt-water or dry com- "What'I claim asnew, and-desire to secure V by Letters Patent, is-

The purple azo dye-stuff hereinbefore dew scribed, which forms in its dry state a jetblack powder and is easily soluble in .cold wa- 6 ter, forming a solution'which is precipitated by the additionof alarge excess of alkali, while small quantities of alkali maybe added: without any apparent change.

,In testimony whereof I have hereuntoset my 70 hand in the presence of twosubscribing wit- OTTO N. .WIT'I. Witnesses: ERNST HEIM,

B. ROI. 

